INVESTIGADORES
SCHLOSS Irene Ruth
artículos
Título:
Phytoplankton variability in the Weddel Sea - Scotia Sea in relation to hydrography.
Autor/es:
SCHLOSS, I.R., ESTRADA, M.
Revista:
POLAR BIOLOGY
Referencias:
Año: 1994 p. 77 - 90
ISSN:
0722-4060
Resumen:
Abstract During the EPOS leg 2 cruise of the RVDuring the EPOS leg 2 cruise of the RV
"Polarstern", carried out in late austral spring of
1988-1989, the composition of phytoplankton in relation
to the distribution of hydrographic parameters
was studied in four successive transects carried out
along 49~ and 47~ across the Weddell-Scotia Confluence
(WSC) and the marginal ice zone (which overlapped
in part). In all transects, a maximum of phytoplankton
biomass was found in the WSC, in surface
waters stabilized by ice melting. Different phytoplankton
assemblages could be distinguished. North of the
Scotia Front (the northern limit of the WSC) diatoms
with Chaetoceros neglectus, Nitzschia spp. and Thalassiosira
9ravida) dominated the phytoplankton community.
This assemblage appeared to have seeded a
biomass maximum which occupied, during the first
transect, an area of the WSC, south of the Scotia Front.
The southernmost stations of the first transect and all
the stations to the south of the Scotia Front in the other
transects were populated by a flagellate assemblage
(with a cryptomonad, Pyramimonas spp. and Phaeocystiscarried out in late austral spring of
1988-1989, the composition of phytoplankton in relation
to the distribution of hydrographic parameters
was studied in four successive transects carried out
along 49~ and 47~ across the Weddell-Scotia Confluence
(WSC) and the marginal ice zone (which overlapped
in part). In all transects, a maximum of phytoplankton
biomass was found in the WSC, in surface
waters stabilized by ice melting. Different phytoplankton
assemblages could be distinguished. North of the
Scotia Front (the northern limit of the WSC) diatoms
with Chaetoceros neglectus, Nitzschia spp. and Thalassiosira
9ravida) dominated the phytoplankton community.
This assemblage appeared to have seeded a
biomass maximum which occupied, during the first
transect, an area of the WSC, south of the Scotia Front.
The southernmost stations of the first transect and all
the stations to the south of the Scotia Front in the other
transects were populated by a flagellate assemblage
(with a cryptomonad, Pyramimonas spp. and PhaeocystisChaetoceros neglectus, Nitzschia spp. and Thalassiosira
9ravida) dominated the phytoplankton community.
This assemblage appeared to have seeded a
biomass maximum which occupied, during the first
transect, an area of the WSC, south of the Scotia Front.
The southernmost stations of the first transect and all
the stations to the south of the Scotia Front in the other
transects were populated by a flagellate assemblage
(with a cryptomonad, Pyramimonas spp. and Phaeocystisdominated the phytoplankton community.
This assemblage appeared to have seeded a
biomass maximum which occupied, during the first
transect, an area of the WSC, south of the Scotia Front.
The southernmost stations of the first transect and all
the stations to the south of the Scotia Front in the other
transects were populated by a flagellate assemblage
(with a cryptomonad, Pyramimonas spp. and PhaeocystisPyramimonas spp. and Phaeocystis
sp.) and an assemblage of diatoms (Corethron
criophilum and Tropidoneis vanheurkii among others)
associated to the presence of ice. During the last three
transects, the flagellate assemblage formed a bloom in
the low salinity surface layers of the WSC zone. The
bulk of the biomass maximum was formed by the
cryptomonad which reached concentrations up to
4 x 106 cells 1-1 towards the end of the cruise. Multivariate
analysis is used to summarize phytoplankton
composition variation. The relationships between the
distribution of the different assemblages and the hydrographic
conditions indicate that the change of
dominance from diatoms to flagellates in the WSC
zone was related to the presence of water masses from
different origin.(Corethron
criophilum and Tropidoneis vanheurkii among others)
associated to the presence of ice. During the last three
transects, the flagellate assemblage formed a bloom in
the low salinity surface layers of the WSC zone. The
bulk of the biomass maximum was formed by the
cryptomonad which reached concentrations up to
4 x 106 cells 1-1 towards the end of the cruise. Multivariate
analysis is used to summarize phytoplankton
composition variation. The relationships between the
distribution of the different assemblages and the hydrographic
conditions indicate that the change of
dominance from diatoms to flagellates in the WSC
zone was related to the presence of water masses from
different origin.and Tropidoneis vanheurkii among others)
associated to the presence of ice. During the last three
transects, the flagellate assemblage formed a bloom in
the low salinity surface layers of the WSC zone. The
bulk of the biomass maximum was formed by the
cryptomonad which reached concentrations up to
4 x 106 cells 1-1 towards the end of the cruise. Multivariate
analysis is used to summarize phytoplankton
composition variation. The relationships between the
distribution of the different assemblages and the hydrographic
conditions indicate that the change of
dominance from diatoms to flagellates in the WSC
zone was related to the presence of water masses from
different origin.